Now that your clients are back from their holiday festivities, chances are they will want to lose weight. With Enter the Zone and Sugar Busters books selling strong, I thought I’d give you a real life example that demonstrates how these books mislead people about what is best for losing weight and keeping it off.If high-carbohydrate diets cause hyperinsulinemia, obesity and type II diabetes (NIDDM), as claimed by these books, how do we explain what is happening to Pima Indians?Pima Indians living in northern Mexico weigh 60-65 pounds less than Pima Indians living in Arizona. The Mexican Pimas’ diet consists largely of potatoes and corn tortillas, both high glycemic index (GI) foods. The Arizona Pimas eat a more Westernized diet with much more protein and fat than their Mexican “cousins.” In Arizona, more than half the Pimas develop NIDDM by age 50 whereas in Mexico, NIDDM is rare and afflicts mainly the elderly. If a high CHO diet containing a lot of high GI foods raises insulin levels and promotes weight gain, why aren’t the high CHO eating Mexican Pimas the ones becoming obese and developing NIDDM? Aside from being inactive, the other major factor leading to obesity and NIDDM among AZ Pimas is the relatively high calorie density or energy density (ED) of their diet compared to that of Mexican Pimas.Genetic differences are not a likely explanation since these two Pima populations arose from the same genetic stock. A study of identical twins showed that there was little difference in ad libitum caloric intake on a high fat or a high-CHO diet if the ED of the two diets was the same. The claim by Sears and Steward in their current books that high-CHO diets lead to hyperinsulinemia and promote obesity and NIDDM is questionable. It is largely the consumption of excess calories in any form, fat, protein or CHO, that causes hyperinsulinemia. A high-ED diet coupled with inactivity often leads to excessive caloric intake, obesity and NIDDM. Even though it is claimed that high insulin levels prevent fat burning and promote fat storage, which lead to obesity, it is much truer that obesity leads to insulin resistance and high insulin levels. High insulin levels are more a result of obesity than a cause.By Dr. Jay Kenney, PhD, RD, FACN